Sputnik – May 12, 2022
A new study has found that the 22-year-long water shortage plaguing the American Southwest and western Mexico is the region’s worst in more than a millennium – a phenomenon dubbed a “megadrought.”
The study, published in Nature Climate Change, found that soil moisture deprivation has exceeded that of a megadrought in the 16th century that was previously the region’s worst known drought.
It’s so bad that University of California Los Angeles geographer Park Williams, the study’s lead author, has warned it would take a prolonged shift in weather patterns to remedy things.
The researchers looked at tree rings to compare the present drought’s intensity with those of years past, since trees generally produce wider rings in wet years and narrower rings in drier years. They found that since 2000, the average soil moisture deficit was twice that of any drought of the past century, with nothing comparable being found until 1,200 years back.
The region has always been quite dry, of course, with four large deserts dominating the terrain and the rest being fairly arid. Indigenous civilization was well-adapted to the precarious conditions, but modern cities have been built without respect to climate – and may soon suffer the consequences.
Reservoirs created by hydroelectric dams, like the famous Hoover Dam outside Las Vegas, Nevada, that holds back Lake Mead, are reaching historic lows. The lake provides the City That Never Sleeps with its freshwater, but has suffered steady water loss since 1983, which has accelerated in recent years, requiring modifications to Hoover Dam’s turbines to allow it to continue producing electricity despite the low water level.